Prospects poised for big years

It is compelling to see a player take the Jadeveon Clowney football career route and progress from highly-touted high school recruit to the first overall pick in the 2014 NFL draft, but that type of prospect doesn't present much of a challenge to an NFL scout.

The real test for those personnel evaluators is finding players whose collegiate career progression isn't quite as clear but whose performance path indicates they can step up their game to the pro level.

Todd McShay's 2015 mock draft highlights a slew of prospects of this nature, but there are other players who may be on the verge of either finding their way into the first round or vastly improving their draft stock via a strong 2014 college season.

Here are five candidates fitting this bill.

Sean Mannion, QB, Oregon State Beavers

To say that Mannion lacks the rushing prowess of many of his competitors is an understatement, as he has only two career games with positive rushing yards and has racked up a grand total of minus-498 rushing yards during his Oregon State tenure.

But what he lacks in ground proficiency he makes up for in passing production. His 69.6 Raw Total QBR mark on pass plays ranked second in the Pac-12 last season. A lot of that was due to throwing 167 passes to Brandin Cooks, but Mannion had a Raw Total QBR of 69 or higher to seven pass-catchers that he targeted 20 or more times.